1. Field of Art
The present invention generally relates to the field of generating maps and specifically to improving quality of existing maps.
2. Background of the Invention
Digital maps, such as those provided by GOOGLE INC., are used in a wide variety of electronic devices, such as car navigation systems and mobile phones. Users rely on digital maps to provide comprehensive and accurate information about roads for purposes including navigation and route guidance. Therefore, the map data must be very precise or problems can develop. For example, if the map data used by a navigation system do not align precisely with the real world, the navigation system could provide inaccurate or nonsensical directions.
There are large public domain map datasets available. One such dataset is the Topologically Integrated Geographic Encoding and Referencing (TIGER) system available from the United States Census Bureau. The TIGER dataset includes streets, roads, water features, and other boundaries in the United States. However, the TIGER dataset lacks enough precision to support global positioning system (GPS)-based navigation and other such needs. For example, the latitude/longitude coordinates of features in the TIGER dataset do not precisely align with the true latitude/longitude coordinates of the features as determined using GPS.
It would be advantageous to improve the accuracy of public domain map datasets such as the TIGER dataset. If such datasets were made more accurate, the datasets could be used to support GPS-based navigation and other technologies.